Loud Thoughts

Life on a Young Planet: The First Three Billion Years of Evolution on Earth Andrew H. Knoll ISBN13: 978-0-691-12029-4 Princeton University Press (March 17, 2003)

Joe Kirschvink, of CalTech, conjectured that Earth was once a snowball. When glaciers crept below 30 degree latitude, they accelerated the cooling down of Earth by reflecting heat back to the space. The cooling sped up the growth of glaciers. Soon, the whole Earth became a giant snowball completely covered in ice.

Millions of years would go by and only the toughest lives, mostly micro-organisms, existed on Earth. Gradually, volcanos and sea activities produced greenhouse gases (CO₂ and methane) to warm up the Earth again.

Once warm, the Earth became an oven. The average sea temperature would reach 40°C. The extreme condition stimulated evolution. At first, anoxic thrived and produced oxygen as a by-product. Millions of years passed again, and the Earth’s atmosphere became oxygen rich. That started the recent oxygen dependent life forms of plants and animals.

Isn’t this just cool!

I had a physical exam with my long-time family doctor recently. He commented that human race has only in recent generations experienced the abundance of foods. Even in our grand-fathers’ time, starvation, from famine or wars, was common. For thousands of years, human race favored those who preserve energy well. The gene pool went into a shock with too much foods. Diabetes, cholesterol, hypertension, etc. ensued and became epidemic. This, he predicted, will again reshape our gene pool.

Geologically, Earth simply does not care. For nearly 4 billion years, Mother Earth has seen lives come and go. Even the entire bilaterian life forms (those with a spine and are symetrical left and right) are a recent addition, let alone homo sapien. Go ahead and mutate, or die out completely, Earth goes on. This brings us to the epilogue of this book, arguably the most interesting part.

If God exists, he would have simply laid down the evolutional rules, set up the physical/chemical environment, and let go. The evidences of his handiwork are in the rocks. The Creationists may be right conceptually, but would have been dead wrong in two categories: God started the world billions of years ago, not thousands; God did not just created plants and animals, he also made germs, virus, and jellyfish.

Another interesting point is on how advanced we are in terms of evolution. Micro-organisms (bacteria, virus, etc.), genetically speaking, have proliferated for billions of years. Oxygen breathing animals have much shorter history and proven to be easily extinguishable too. The fact that human being can think and make tools does not make us more advanced, merely more complex. Micro-organisms have a much better chance of wiping out human race than the other way around. In fact, it is not a stretch to consider that we exist only to host them. If God has a favorite among all life forms, we are not.